Method and apparatus for manufacturing electrical cables



Sept 20, 1938. M. KLEIN 2,130,394

METHOD AND APPARATUS FOR MANUFACTURING ELECTRICAL CABLES Filed April 27, 1935 s Sheets-Sheet 1 Sept. 20, 1933. M. KLEIN METHOD AND APPARATUS FOR MANUFACTURING ELECTRICAL CABLES Filed April 27, 1935 3 Sheets-Sheet 2 Sept. 20, 1938. M. KLEIN 2,130,394

' METHOD AND APPARATUS .FOR MANUFACTURING ELECTRICAL CABLES Filed April 27, 1935 a Sheets-Sheet a [IE J22 J24 J26 J16 4728? ,ziwenzzm M KL E/N z27 v iiarnezy.

Patented Sept. 20, 1938 STATES FATENT GFFECE Maurus Klein, Lausanne, Switzerland Application April 27, 1935, Serial No. 18,532 In Switzerland April 4, 1931 3 Claims.

This invention relates to an improvement in a method and apparatus for manufacturing electrical for signalling, particularly for telephone transmission purposes.

t is an object of the invention to increase the eiiiciency of such manufacture.

It is another object of the invention to increase the preciseness of manufacture and to equalize the capacities between the conductors forming pairs in such cables, and to unify the capacities between each two of such pairs.

These and other objects of the invention will more fully appear from the following specification.

This application forms a continuation in part of my co-pending application Serial No. 573,195, filed November 5, 1931.

In the said co-pending application the manufacture of electrical cables for telephone transmission has been described comprising pairs of twisted conductors, two such pairs being again twisted together, forming a set. Unbalances of capacities between the conductors of the pairs, and between two such pairs forming a set, are intended to be removed by my co-pending application. It has been accomplished by directly braking the conductors while twisting them into pairs, particularly by applying frictional brakes or deformation brakes on each of the conductors during the twisting operation. I preferred the use of deformation brakes because they can identically be built and equally adjusted with same accuracy, whereby applying of the same tension to each of the conductors to be twisted into a pair can be secured.

I further described in this co-pending application the way of adjusting such brakes by first making short trial lengths of the pair to be produced and investigating its qualities in order to adjust one or the other brake, if necessary, until their action is rendered equal. I further disclosed a method of securing the crossings of the twisted conductors at the proper places, such as by binding them tightly at suitable points. To eliminate any tensions in the conductors before passing the brakes, I suggested to draw the strands of the insulated conductors from loosely wound coils, particularly from cones around which the strands have been loosely wound before.

By the present invention, this method of directly braking the conductors, or the sets of conductors, to be twisted is improved. Furthermore, a cable twisting machine suitable for performing this improved method and comprising brakes acting directly on the strands, or set of strands, preferably to be unwound from loosely wound coils and to be twisted into pairs, or sets of pairs, is concerned.

The invention may be more fully described in 5 the following specification.

In the drawings, Fig. l is a side elevation of a machine for winding two strands of the insulated conductors into a loosely wound coil; Fig. 2 is a side elevation, partly in cross-section, of a machine for twisting the two strands from the coils into pairs and, in the same operation, the pairs into sets, or groups; Fig. 2a shows a detail of the machine according to Fig. 2, partly in cross-section; Fig. 3 shows a somewhat altered detail of the machine according to Fig. 2; Fig. 3a shows a particular feature of brakes to be used in such a machine, seen in direction of arrow a in Fig. 3.

In Fig. l, a cone l having a lower cylindrical part 8 is positioned upon a shaft 2 which is connected with a bevelled gear iii, which meshes with another bevelled gear 9 rotatably mounted on a support i8 which is mounted on a frame 6, in the upper part of which the shaft 2 is rotatably held. 'On the shaft IS, on the rear side of the support it, is fixed a disc 5 driven with desired speed by a belt 3 and another disc #2 on the shaft of a motor 5. The upper end of shaft 2 may have a square cross section fitting into a correspondingly shaped hole in cone I, so that the latter one is rotated with desired speed around its vertical axis. On the upper side of frame ii a table I? is fixed having a guide 89 with two holes ill, 82 through which the strands i 5, l2, respectively, are drawn from suitable supply rolls i3, it, respectively, which are exchangeably supported by a suitable frame 55.

In operation, the strands ll, 92 are drawn through the holes 85, 82 and first wound, in the 4 way shown, helically around the cylindrical part 8 and the conical part of the cone l, and fixed with their ends at 33 to one of the rods i6, which are removably mounted on the upper side of the cone 7. If rotating the-cone around its vertical axis by means of the motor l, the strands H, H. are first wound around the cylindrical part 8 of the cone 5 in a certain number of windings which, after the cylindrical part 8 has been quite tightly covered in this way by a layer of these strands, are pushed up onto the conical part I when continuing the winding up of the strands M, iii, whereby the subsequent windings displace the formerly wound up windings. The so pushed up windings are now quite loosely lying around the cone 1. This operation continues until a coil of a desired number of windings has been wound. Thereupon the strands II, I2 are cut off on their lower ends and the cone 7 is removed from the shaft 2. No such cutting off is necessary if coils are wound upon the cone 1 till the supplies I3, I4 are exhausted.

It is to be noted that by this operation no twisted pairs of strands are produced, but that a coil has been made consisting of two still entirely separate strands. One may call this a doublecoil.

In Figs. 2, 2a, 3 and 3a the identical reference numbers have the same significance.

The machine for twisting the strands into twisted pairs and thereupon into sets, or groups, comprises a base plate 84 and a frame 85, 85, 87, 88. On the base 84 a bearing I8 is mounted in which the vertical main shaft I! of the machine is journaled, on the upper end of which a bevelled gear 20 is fixed, meshing with another bevelled gear 2| mounted on a driving shaft 89 which is journaled in a bearing of the frame-part 87. Shaft 89 is driven with desired speed by a motor (not shown).

A gear 22 is fixed to the bearing I8 so that it cannot rotate. The gears 23, 24 are rotatably mounted on arms 93, 94 by means of bearings 9!, 92. On the upper end of the shafts 95, 96, gears AI, A2 are mounted meshing with gears B1, B2,

respectively, the shafts 91, 98 of which are journaled in bearings 99, I00, respectively. On shaft 91 a gear 21 is mounted meshing with the gear 29, while on shaft I00 a gear 28 is mounted meshing with gear 30.

Table 38 is mounted on shaft HM and journaled in a bearing I04. Shaft IOI carries a gear 29 meshing with gear 21. Shaft I02 carries a gear 30 meshing with a gear 28. The bearings 9|, 99, I04 are fixed to an arm 93; the bearings 92, I00, I03 are mounted on an arm 94. The arms 93, 94 are fixed to the sleeve I05 which in turn is fixed to the shaft I I and rotate therefore with the shaft I1.

A sleeve 25 is rotatably mounted'around the shaft I1 and connected at its lower end with a gear I06, which meshes with the gear I01 fixed on the upper end of shaft I08 which is journaled in a bearing I09 fixed on arm IIO of sleeve I05. A gear 25 is fixed on the lower end of shaft I08 and meshes with the stationary gear 22 fixed to the bearing I 8. On the upper end of sleeve 25 a gear 3| is fixed. On a shaft III which is journaled in a bearing of arm I I2 and connected with the gear 32 a gear al is fixed and meshes with a gear bl which is connected by a shaft with the gear 34, which meshes with gear 36. In the same way, gear 33 is connected with gear (12 which meshes with gear D2 which is connected with agear 35 which meshes with gear 31. The arms 'II2, II3 are fixed at II4 to the shaft II. A bearing H5 is provided at the end of arm II 2, and a bearing I I6 on the end of arm I I3. A bearing I I1 is provided at the end of an arm I I8, and a bearing H9 at the end of an arm I20, which are fixed at I2I to the shaft II. Direct acting brakes, in

this embodiment of the invention in the form deformation brakes I are journaled in the bearings H5, H1, and identical brakes II are journaled in the bearings H5, H9. The pivots of these brakes are hollow so that the strands I I, I2 and II', I2, respectively, may enter and leave the brakes through these holes.

The gear 36 is fixed to the lower pivot of brake I and the gear 31 is fixed to the lower pivot of brake II. Another gear 42 is fixed on the upper end of brake I and meshes with a gear 44, the shaft of which is journaled in the arm H8 and fixedly connected with another gear 45 which meshes with the gear 48. In the same way, gear 43 is connected with the upper end of the brake II and meshes with the gear 45, the shaft of which is journaled in the arm I2I and fixedly connected with another gear 45 which meshes with the gear 49.

The gear 48 is journaled in the bearing III independently of the pivot of the brake I and bears a table I22 which is fitted with suitable devices for lacing the twisted strands. A supply roll 59 of yarn is pivotally fixed on the table and the yarn drawn through an ear I24 around the pair of strands. In the same way, a gear 49 is pivotally mounted in the bearing H9 and bears a table I23 with lacing means 5|, I25.

On the lower side of brake I a flexible hollow shaft I25 is fixed and connected with a bell I21 which is rotatably mounted in a bracket I28 fixed on the outside of the bearing I I5. With the hollow pivot of brake II a hollow flexible shaft I29 is connected extending to a bell I30 being rotatably mounted in a bracket I3I fixed on the outside of the bearing II5.

Near the upper end of shaft I I a wheel I9 having arms I32 is fixed. This wheel glides in a guide I33 being fixed to the upper part 86 of the machine frame. On the arms I32 the twisting guides 52, 53 are mounted.

On the upper part 88 of the frame another twisting die 54 for the set or group of strands is mounted.

In operation, two cones I, II, upon each of which a pair of strands II, I2 and II, I2 have been wound in the way as described in connection with Fig. 1, are positioned upon the tables 38, 39, and the rods I6 are removed. The upper ends of the strands II, I2 are drawn through bell I21, flexible shaft I26, hollow pivot of brake 1, between the rolls of the latter one, and then through the upper hollow pivot of the brake, the twisting die 52 and then through the other die 54. Said twisting dies exert the well known action upon the pair of strands passing them consisting therein that the strands are slightly pressed together and against the walls of the dies when being drawn through them whereby friction is caused between the strands and the walls of the dies sufficient to prevent the strands from substantially rotating within the dies and around each other. The deformation brake I comprises several rolls I34, each of them having two circumferential grooves in which the strands II, I2 are positioned and deformed, so as to exercise upon them the intended brake action. The two strands are then twisted around each other by the die 52. In same way, the strands II, I2 are drawn from the cone 4I into the bell I30, through the hollow flexible shaft I29 and the hollow pivot of brake II between the rolls of it and then through the hollow die 53 and twisted thereby around each other.

The strands being drawn o'if loosely wound coils 40, 4|, a negligible tension exists in them when entering the deformation brakes, the action of which determines therefore substantially the tension in the strands which are absolutely equal inter se, and therefore also an equal and uniform twisting results with surprisingly small unbalances of the capacities of the pairs of insulated wires. Two pairs of strands of such quality being then twisted into a set, or group, at the die 54, it appears therefrom that "also the set will be of highest uniformity. It is'to be understood that such set 135 is then drawn in the well known way upon a roll which is driven so as to apply the wanted tension upon all the strands to be combined in the group, or set.

The shaft 69 rotates the shaft I1 in a wanted direction with the wanted number of turns per minute. Consequently, the tables 38, 39 with the cones I, II, furthermore the brakes I, II and the lacing devices 56, I24, 52 and 5|, I25, 53, respectively, are rotated with the same speed by the shaft "I1.

At the same time, the strands are drawn from thercoils. While unwinding thecoils, each strand would be twisted once around its own axis if one winding is drawn off from the coil. Therefore each coil has to be rotated around its own axis so that it makes one turn while one winding is drawn 01f from it, and in such a sense that this twisting of the strand is avoided. Thereby the point of drawing off the'strand from the coil virtuallyremains at thesame place relative to the rotating shaft. This well known so-called back rotation is achieved by the gears 23, AI, BI, 21, 29 and 24, A2, B2, 28, 35, respectively, which are moved accordingly as the tables 38, 39 on the arms 93, 94 are rotated by the shaft I1 and the gears23, 24 are therefore rolled off the. stationary gear 22. These gears may be exchangeable in order to take care of diiferent average diameters of the coils. By properly dimensioning these gears also another result is obtained, as to twisting the strands II, I2 and II, I2 passing the brakes I, II. These. brakes are rotated around their own axis by the gears 32, (H, bl, 34, 36 and 33, a2, b2, 35, 31, respectively. By exchanging gears AI, BI, aI, bl, A2, B2, a2, b2, different speeds of the brakes relative to the coils are obtained. Supposed that the strands are drawn through the brakes with the same speed, by increasing the relative speed of rotation of the brakes also the number of twists per unit of lengths of the twisted pair is increased, and vice versa.

The gears AI, BI, and A2, B2 may be dimensioned so that the place from which the strands are drawn off the coils retains its position relatively to the plane of the co-ordinated brake during rotation of the latter one. Let me take, for example, that the brakes are making 100 turns during a minute, and that ten windings are drawn off per minute from the coils, then the coil has to make 110, or 90, turns per minute, as the case may be, and the gears referred to are suitable to be dimensioned. Consequently, the pair of strands passing from the brake I34 through the die 52 will be twisted 100 times. Supposing that the shaft I1 makes 60 turns per minute, the pairs of strands passing from the die 52 to the die 54 will be twisted 60 times. But any other relation of the speeds of these rotations may be accomplished provided that the above described synchronization between drawing oif the strands from a loose double coil and rotation of a coordinated brake around its own axis is maintained and thereby any twist otherwise put into the pair of strands on its way from the double coil to the brake, is compensated.

The brakes rotate the strands, passing them in parallel, around the longitudinal axis of the brake, whereby the strands are twisted in passing to the die 52. On the way to the die, a yarn I35 may be twisted around the twisted pair of strands in order to fix their places of crossings.

The yarn is drawn from a spool 56 rotatably' mounted on the. table I22. In order to twist this yarn I35 around the pair of strands, the spool "56 and the ear I24 are to be rotated around the pair of strands, and this is achieved by means of the gears 48, 46, 44, 42, the latter one being fixed to the brakes, the first one to the table I22. In the same way, a yarn I36 may be twisted around the other pair of strands leaving the brake II; the yarn is drawn off from the spool 5!, and the table I22 is rotated by the gears 49, 41, 45, 43.

The thus equally twisted pairs of strands I31, I38 now pass the die 54 wherein the pairs are twisted into a group due to rotation of the shaft II with the dies 52, 53 and due to the drawing off of the strands I36 by a roll I15, diagrammatically shown in dotted lines, which is driven by ashaft I16, shown in the same way, in the directionof the arrow.

In order to adjust the speed of rotation of the brakes, also the gears 25, I61 may be suitably chosen. Gear 25 is driven by the stationary gear 22.

By varying the. speed of the shaft 1| and the speed of drawing oii the four strands I33, the number of twists in the group per unit of length can be adjusted.

The pair of strands may also be drawn through brakes having rolls I 86 with only one groove each. Both strands are then passing the same groove, and the twisting is already done at the point where the strands enter the brake. If, however,

the twisting is to be done after the strands have passed the brakes, then the rolls may be arranged as shown in Figs. ,3, 30.. On a plate I66 pairs of grooved rolls 55, 55'; 56, 56'; 51, 51; 58, 58', 59, 59' are pivotally mounted and the strands I I, I2 separately drawn over the rolls 55, 56, 51,58, 59 and 55, 56, 51, 58', 59, respectively. The deformation and thereby the action of the brake may be adjusted at a desired degree by turning the gear I65 by means of the worm I61 and handle I66. A dial I68 may be provided in order to facilitate the equal adjustment of the various brakes (in this exemplification two). If rotating the gear I65 the screw I 64 is rotated within a nut I69 provided on the slide I63, which is slidably held in guides I6I, I62 of the plate I60 and pivotally bears the three middle pairs of rolls. By moving this slide I63 to the left in the drawings, the deformation of the strands will be increased and thereby the braking action upon them. The thus twisted pairs of strands are then led through the guides I16, "I in the table I69 which is fixed to one of the arms I32, and they are then twisted together with the strands'II', I2 passing the guides I16, III of the tube I12 into a group, or set, by means of the disc 54.

It is to be understood that by increasing the number of brakes and cones, three and more pairs of insulated conductors (strands) can be twisted together and into groups of any desired higher order. Such groups may be used in a star-or in a phantom-or any other usual or suitable electrical connection for telephone and other transmission of signals, sounds, talks, or the like.

In the embodiment of the invention according to Figs. 3, 3a. no twisting around of yarn is necessary, and it may also be omitted in the other exemplification of the invention shown in Fig. 2.

According to the invention, two twists, of pairs and of groups, are performed in one operation with greatest accuracy and symmetrical distribution of capacities, using a single adjusting The very

' scribed in its broadest aspect by the appended claims.

What I claim is:

1. An apparatus for twisting into pairs strands of insulated electrical conductors drawn through it and such pairs into groups, comprising a number of supporting means for coils of loosely wound untwisted pairs of said strands; a number of adjustable deformation brakes each adapted to act directly and simultaneously upon a pair of said strands, means for adjusting each of said brakes, and means for rotating each of said brakes around its own axis substantially coinciding with the direction of travel of said strands through the brake; a first twisting die stationary arranged in the path of all said strands; a number of second twisting dies, a second twisting die each arranged in the path of a pair each of said strands from a brake to said first twisting die, the numbers of said supporting means, said brakes and said second twisting dies being equal; means for rotating said supporting means, said brakes and said second twisting dies with equal speed around a common axis; and means for back-rotating said supporting means relative to said brakes rotating around their own axis, so that untwisted loose pairs of strands under no tension are delivered to said brakes; thereby each pair of said strands being twisted on its way from a brake to a second twisting die, and the twisted pairs so obtained being twisted into groups when passing said first twisting die. I

2. In an apparatus as described in claim 1, said means for rotating said supporting means, said brakes and said second twisting dies around a common axis being exchangeable.

3. A method of manufacturing twisted groups of a plurality of twisted pairs of strands of insulated electrical conductors, comprising the steps of winding pairs of parallel strands into loosely Wound coils, drawing said pairs off from said coils and simultaneously back-rotating said coils, introducing a still untwisted pair each of loose strands into a directly acting brake each, rotating with equal speeds each of said brakes around its own axis substantially coinciding with the direction of travel of said strands through said brake, drawing said pairs from said brakes through individual twisting dies stationary arranged relative to said brakes, thereby twisting said pairs of strands, rotating said brakes and said twisting dies simultaneously and with equal speed around a common axis, drawing said twisted pairs through a common stationary twisting die and twisting thereby said pairs into groups.

MAURUS KLEIN. 

